1. Field of the Invention
The present invention relates to a loudspeaker system having wide-directional characteristics utilized for speakers of, for example, HiFi-audio systems, acoustic measuring equipments and the like, particularly, in which a plurality of speakers are arranged at peripheral surface portions of a polyhedron or spherical body thereby allowing good quality sound reception by a listener from various directions.
2. Relevant Art of the Invention
One example of a loudspeaker of the type mentioned above is disclosed in Japanese Utility Model Laid-open (KOKAI) Publication No. SHO 59-31105.
This discloses a loudspeaker having a body of a regular dodecahedron shape, as a polyhedron shape, having respective surfaces to which uni-molf oscillators and diaphragms (oscillating plates) are arranged, respectively, thereby to listen sounds from the various directions around the polyhedron body.
However, it is generally known, in a speaker of the conventional structure, that a high-frequency attenuation is caused except along a transverse (frontal) surface of an axial line of the speaker, and in the described prior art, in which the uni-molf oscillators and diaphragms are arranged on the respective surfaces of the polyhedron body, the respective uni-molf oscillators are necessarily not arranged on the same one plane and arranged at positions inclined with each other. Accordingly, because of the fact that the high frequency attenuation is caused except along the frontal surface on the axial line of each of the uni-molf oscillators, it is difficult to listen to the sounds, in good quality, in the range of low to high frequencies at all the positions at the entire peripheral surface of the speaker system.
In the HiFi audio speaker, the flatness of the frequency for maintaining constant the sound pressure even if the frequency varies was required. Further, it was also required for the speaker for specially measuring acoustic sounds to be provided with the flatness of the frequency and non-directional property thereof, but no countermeasure was substantially taken, in the conventional art, against the high frequency attenuation due to the inclined arrangement of the respective speakers.